1231221088961 has 2 divisors, whose sum is σ = 1231221088962. Its totient is φ = 1231221088960.

The previous prime is 1231221088931. The next prime is 1231221089003. The reversal of 1231221088961 is 1698801221321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 666966222400 + 564254866561 = 816680^2 + 751169^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1231221088961 is a prime.

It is not a weakly prime, because it can be changed into another prime (1231221088931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615610544480 + 615610544481.

It is an arithmetic number, because the mean of its divisors is an integer number (615610544481).

Almost surely, 2^{1231221088961} is an apocalyptic number.

It is an amenable number.

1231221088961 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231221088961 is an equidigital number, since it uses as much as digits as its factorization.

1231221088961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 82944, while the sum is 44.

The spelling of 1231221088961 in words is "one trillion, two hundred thirty-one billion, two hundred twenty-one million, eighty-eight thousand, nine hundred sixty-one".